fs: dlm: fix cleanup pending ops when interrupted

Immediately clean up a posix lock request if it is interrupted
while waiting for a result from user space (dlm_controld.)  This
largely reverts the recent commit b92a4e3 ("fs: dlm: change
posix lock sigint handling"). That previous commit attempted
to defer lock cleanup to the point in time when a result from
user space arrived. The deferred approach was not reliable
because some dlm plock ops may not receive replies.

Cc: stable@vger.kernel.org
Fixes: b92a4e3 ("fs: dlm: change posix lock sigint handling")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>

Author: Alexander Aring

fs/dlm/plock.c

@@ -30,8 +30,6 @@ struct plock_async_data {
 struct plock_op {
 	struct list_head list;
 	int done;
-	/* if lock op got interrupted while waiting dlm_controld reply */
-	bool sigint;
 	struct dlm_plock_info info;
 	/* if set indicates async handling */
 	struct plock_async_data *data;
@@ -167,12 +165,14 @@ int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
 			spin_unlock(&ops_lock);
 			goto do_lock_wait;
 		}
-
-		op->sigint = true;
+		list_del(&op->list);
 		spin_unlock(&ops_lock);
+
 		log_debug(ls, "%s: wait interrupted %x %llx pid %d",
 			  __func__, ls->ls_global_id,
 			  (unsigned long long)number, op->info.pid);
+		do_unlock_close(&op->info);
+		dlm_release_plock_op(op);
 		goto out;
 	}
 
@@ -434,19 +434,6 @@ static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
 		if (iter->info.fsid == info.fsid &&
 		    iter->info.number == info.number &&
 		    iter->info.owner == info.owner) {
-			if (iter->sigint) {
-				list_del(&iter->list);
-				spin_unlock(&ops_lock);
-
-				pr_debug("%s: sigint cleanup %x %llx pid %d",
-					  __func__, iter->info.fsid,
-					  (unsigned long long)iter->info.number,
-					  iter->info.pid);
-				do_unlock_close(&iter->info);
-				memcpy(&iter->info, &info, sizeof(info));
-				dlm_release_plock_op(iter);
-				return count;
-			}
 			list_del_init(&iter->list);
 			memcpy(&iter->info, &info, sizeof(info));
 			if (iter->data)
@@ -465,8 +452,8 @@ static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
 		else
 			wake_up(&recv_wq);
 	} else
-		log_print("%s: no op %x %llx", __func__,
-			  info.fsid, (unsigned long long)info.number);
+		pr_debug("%s: no op %x %llx", __func__,
+			 info.fsid, (unsigned long long)info.number);
 	return count;
 }